The field of the disclosure relates generally to pumping systems in a gas turbine engines and, more particularly, to a method and system for pumping oil in a gas turbine engine using a centrifugal pump.
Scavenge oil, i.e., oil drained to an oil sump after lubricating bearings in gas turbine engines, is typically sent to a scavenge oil tank after lubricating the bearings. At least some known methods of transporting scavenge oil to a scavenge oil tank include a gravitational drain through a hot frame. As gas turbine engines become more powerful, the temperatures the hot frame is exposed to also increase. Transporting scavenge oil in the hot frame can cause the scavenge oil to coke because of the high temperatures the hot frame is exposed to. To reduce scavenge oil coking, cooling air is supplied to the hot frame to cool the scavenge oil as it is transported through the hot frame. Additionally, the hot frame strut thickness is increased to protect the scavenge oil drain piping. An additional cooling air system and a thicker hot frame strut adds weight to the gas turbine engine.